Checking the cement job at BP's well: An editorial

Probes of the Deepwater Horizon explosion and subsequent oil spill have already found numerous problems with how BP designed and managed the drilling of its dangerous Macondo well.

PHOTO BY TED JACKSONOil skimmers try to clean up oil spilled after the Deepwater Horizon disaster in the Gulf of Mexico in April 28.

But although BP's decisions appear to have greatly contributed to the causes of the disaster, other firms involved also may have played a role -- and investigators need to make sure everyone at fault is held responsible.

The latest troubling finding comes from President Barack Obama's National Oil Spill Commission, whose investigators found that a cement mixture used by Halliburton to seal the well was unstable. Even worse, the investigators concluded that Halliburton knew about the cement problems because of previous failed tests, yet used the mixture anyway.

"Had the cement done its job, the hydrocarbons would have been isolated,and there should not have been a blowout," said a commission staffer.

That's very troubling.

The cement mixture was found to be unstable in nine different tests conducted by Chevron at the commission's requests.

BP's own investigation blamed Halliburton for the blowout, which led to the spilling of nearly 5 million barrels of oil into the Gulf of Mexico. But the commission and industry experts said that a cement failure by itself does not cause a blowout.

Investigators may very well conclude that the cement job was botched. But several BP decisions at the well that put cost-cutting over safety compounded the risks of a blowout. BP used fewer so-called centralizers to stabilize the pipe than Halliburton recommended. BP also did not do a test of the cement job, opting instead to send the crew hired for that job home. And the company's well design also left an open space up the side of the hole where gas could have entered unabated.

That does not mean Halliburton is off the hook, and investigators need to establish the company's role in the disaster.

Halliburton said the cement mixture the commission tested used different additives than what went down the Macondo well. The commission said it got the list of ingredients from Halliburton, but the company said it had used a unique mix of cement and additives and that the commission used "off-the-shelf" ingredients. U.S. District Judge Carl Barbier ordered Halliburton to provide samples of the actual mix used at the well to the commission, and that should be tested to settle the issue.

One thing seems clear after months of investigations by the commission and other government bodies. The Deepwater Horizon disaster did not have a singular cause, but rather multiple failures and wrong decisions that led to one of the nation's worst environmental disasters. And all the parties at fault need to be held accountable for their role.